RE: Twist 3D 60 ARF
I was originally thinking of going with the 15cc engine but I looked at the pe reivers prop thrust calculator and figured I would get 12 to 13 lbs thrust out of the 20cc engine which is what I wanted for 3d flight (I'm getting 8100 rpms). I'm not a 3d expert but I'm slowly learning and at 7.5 to 8 lbs AUW (with the 15cc engine), I didn't think the 15cc would work very well at all.